The Lötschenlücke connects the Lötschental to the valley of a glacier with a length of about what in 2014?
23 km
-1
Section::::Abstract.
Lötschenlücke
20017630
-1
Section::::Abstract.
Lötschenlücke
20017630
-1
Section::::Abstract.
Aletsch Glacier
283809
-1
Section::::Abstract.
Aletsch Glacier
283809